There are thousands of makes and models of shield generators which can be chained or tuned to a pilot's preferences. Standard shield generators simply provide a certain amount of protection at a particular recharge rate for so much energy usage per second. Other models may be able to reflect a particular type of gun while being weak against another type (i.e. 20% chance of reflecting a energy blast while being weak against ballistic weapons). Other shields may affect a spacecraft's stealth, and others yet may provide a strong forward shield used for ramming.